What is the primary function of $Cu$ ions released by $IUDs$?

Which of the following is an ideal contraceptive for females who want to delay pregnancy and space out children?

Diaphragms are contraceptive devices used by females. Choose the correct option from the statements given below:
$i$. They are introduced into the uterus
$ii$. They are placed to cover the cervical region
$iii$. They act as physical barriers for sperm entry
$iv$. They act as spermicidal agents

An example of a hormone-releasing $IUD$ is:

Progestasert and $LNG-20$ are the examples of

Which $IUD$ increases the phagocytosis of the sperms within the uterus?